An application programming interface (API) is a way for one program
to talk to another program. For example, Mr. Code's Wild Ride has an
API that allows other programs to access public data about its
students and projects. This is useful if a program needs to create
user accounts based on Mr. Code's students, for example.
There are many ways to call an API. A common way is to make an HTTP
request to a specific URL, and receive a response in JSON format.
This is an example of a representational state transfer (REST) API.